+++ /dev/null
-/**
- * \file mlt_transition.c
- * \brief abstraction for all transition services
- * \see mlt_transition_s
- *
- * Copyright (C) 2003-2009 Ushodaya Enterprises Limited
- * \author Charles Yates <charles.yates@pandora.be>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-
-#include "mlt_transition.h"
-#include "mlt_frame.h"
-#include "mlt_log.h"
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-/* Forward references */
-
-static int transition_get_frame( mlt_service this, mlt_frame_ptr frame, int index );
-
-/** Initialize a new transition.
- *
- * \public \memberof mlt_transition_s
- * \param this a transition
- * \param child the object of a subclass
- * \return true on error
- */
-
-int mlt_transition_init( mlt_transition this, void *child )
-{
- mlt_service service = &this->parent;
- memset( this, 0, sizeof( struct mlt_transition_s ) );
- this->child = child;
- if ( mlt_service_init( service, this ) == 0 )
- {
- mlt_properties properties = MLT_TRANSITION_PROPERTIES( this );
-
- service->get_frame = transition_get_frame;
- service->close = ( mlt_destructor )mlt_transition_close;
- service->close_object = this;
-
- mlt_properties_set_position( properties, "in", 0 );
- mlt_properties_set_position( properties, "out", 0 );
- mlt_properties_set_int( properties, "a_track", 0 );
- mlt_properties_set_int( properties, "b_track", 1 );
-
- return 0;
- }
- return 1;
-}
-
-/** Create and initialize a new transition.
- *
- * \public \memberof mlt_transition_s
- * \return a new transition
- */
-
-mlt_transition mlt_transition_new( )
-{
- mlt_transition this = calloc( 1, sizeof( struct mlt_transition_s ) );
- if ( this != NULL )
- mlt_transition_init( this, NULL );
- return this;
-}
-
-/** Get the service class interface.
- *
- * \public \memberof mlt_transition_s
- * \param this a transition
- * \return the service class
- * \see MLT_TRANSITION_SERVICE
- */
-
-mlt_service mlt_transition_service( mlt_transition this )
-{
- return this != NULL ? &this->parent : NULL;
-}
-
-/** Get the properties interface.
- *
- * \public \memberof mlt_transition_s
- * \param this a transition
- * \return the transition's properties
- * \see MLT_TRANSITION_PROPERTIES
- */
-
-mlt_properties mlt_transition_properties( mlt_transition this )
-{
- return MLT_TRANSITION_PROPERTIES( this );
-}
-
-/** Connect this transition with a producers a and b tracks.
- *
- * \public \memberof mlt_transition_s
- * \param this a transition
- * \param producer a producer
- * \param a_track the track index of the first input
- * \param b_track the track index of the second index
- * \return true on error
- */
-
-int mlt_transition_connect( mlt_transition this, mlt_service producer, int a_track, int b_track )
-{
- int ret = mlt_service_connect_producer( &this->parent, producer, a_track );
- if ( ret == 0 )
- {
- mlt_properties properties = MLT_TRANSITION_PROPERTIES( this );
- this->producer = producer;
- mlt_properties_set_int( properties, "a_track", a_track );
- mlt_properties_set_int( properties, "b_track", b_track );
- }
- return ret;
-}
-
-/** Set the starting and ending time for when the transition is active.
- *
- * \public \memberof mlt_transition_s
- * \param this a transition
- * \param in the starting time
- * \param out the ending time
- */
-
-void mlt_transition_set_in_and_out( mlt_transition this, mlt_position in, mlt_position out )
-{
- mlt_properties properties = MLT_TRANSITION_PROPERTIES( this );
- mlt_properties_set_position( properties, "in", in );
- mlt_properties_set_position( properties, "out", out );
-}
-
-/** Get the index of the a track.
- *
- * \public \memberof mlt_transition_s
- * \param this a transition
- * \return the 0-based index of the track of the first producer
- */
-
-int mlt_transition_get_a_track( mlt_transition this )
-{
- return mlt_properties_get_int( MLT_TRANSITION_PROPERTIES( this ), "a_track" );
-}
-
-/** Get the index of the b track.
- *
- * \public \memberof mlt_transition_s
- * \param this a transition
- * \return the 0-based index of the track of the second producer
- */
-
-int mlt_transition_get_b_track( mlt_transition this )
-{
- return mlt_properties_get_int( MLT_TRANSITION_PROPERTIES( this ), "b_track" );
-}
-
-/** Get the in point.
- *
- * \public \memberof mlt_transition_s
- * \param this a transition
- * \return the starting time
- */
-
-mlt_position mlt_transition_get_in( mlt_transition this )
-{
- return mlt_properties_get_position( MLT_TRANSITION_PROPERTIES( this ), "in" );
-}
-
-/** Get the out point.
- *
- * \public \memberof mlt_transition_s
- * \param this a transition
- * \return the ending time
- */
-
-mlt_position mlt_transition_get_out( mlt_transition this )
-{
- return mlt_properties_get_position( MLT_TRANSITION_PROPERTIES( this ), "out" );
-}
-
-/** Process the frame.
- *
- * If we have no process method (unlikely), we simply return the a_frame unmolested.
- *
- * \public \memberof mlt_transition_s
- * \param this a transition
- * \param a_frame a frame from the first producer
- * \param b_frame a frame from the second producer
- * \return a frame
- */
-
-mlt_frame mlt_transition_process( mlt_transition this, mlt_frame a_frame, mlt_frame b_frame )
-{
- if ( this->process == NULL )
- return a_frame;
- else
- return this->process( this, a_frame, b_frame );
-}
-
-/** Get a frame from this transition.
-
- The logic is complex here. A transition is typically applied to frames on the a and
- b tracks specified in the connect method above and only if both contain valid info
- for the transition type (this is either audio or image).
-
- However, the fixed a_track may not always contain data of the correct type, eg:
-<pre>
- +---------+ +-------+
- |c1 | |c5 | <-- A(0,1) <-- B(0,2) <-- get frame
- +---------+ +---------+-+-----+ | |
- |c4 | <------+ |
- +----------+-----------+-+---------+ |
- |c2 |c3 | <-----------------+
- +----------+-------------+
-</pre>
- During the overlap of c1 and c2, there is nothing for the A transition to do, so this
- results in a no operation, but B is triggered. During the overlap of c2 and c3, again,
- the A transition is inactive and because the B transition is pointing at track 0,
- it too would be inactive. This isn't an ideal situation - it's better if the B
- transition simply treats the frames from c3 as though they're the a track.
-
- For this to work, we cache all frames coming from all tracks between the a and b
- tracks. Before we process, we determine that the b frame contains someting of the
- right type and then we determine which frame to use as the a frame (selecting a
- matching frame from a_track to b_track - 1). If both frames contain data of the
- correct type, we process the transition.
-
- This method is invoked for each track and we return the cached frames as needed.
- We clear the cache only when the requested frame is flagged as a 'last_track' frame.
-
- * \private \memberof mlt_transition_s
- * \param service a service
- * \param[out] frame a frame by reference
- * \param index 0-based track index
- * \return true on error
- */
-
-static int transition_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
-{
- int error = 0;
- mlt_transition this = service->child;
-
- mlt_properties properties = MLT_TRANSITION_PROPERTIES( this );
-
- int accepts_blanks = mlt_properties_get_int( properties, "accepts_blanks" );
- int a_track = mlt_properties_get_int( properties, "a_track" );
- int b_track = mlt_properties_get_int( properties, "b_track" );
- mlt_position in = mlt_properties_get_position( properties, "in" );
- mlt_position out = mlt_properties_get_position( properties, "out" );
- int always_active = mlt_properties_get_int( properties, "always_active" );
- int type = mlt_properties_get_int( properties, "_transition_type" );
- int reverse_order = 0;
-
- // Ensure that we have the correct order
- if ( a_track > b_track )
- {
- reverse_order = 1;
- a_track = b_track;
- b_track = mlt_properties_get_int( properties, "a_track" );
- }
-
- // Only act on this operation once per multitrack iteration from the tractor
- if ( !this->held )
- {
- int active = 0;
- int i = 0;
- int a_frame = a_track;
- int b_frame = b_track;
- mlt_position position;
- int ( *invalid )( mlt_frame ) = type == 1 ? mlt_frame_is_test_card : mlt_frame_is_test_audio;
-
- // Initialise temporary store
- if ( this->frames == NULL )
- this->frames = calloc( sizeof( mlt_frame ), b_track + 1 );
-
- // Get all frames between a and b
- for( i = a_track; i <= b_track; i ++ )
- mlt_service_get_frame( this->producer, &this->frames[ i ], i );
-
- // We're holding these frames until the last_track frame property is received
- this->held = 1;
-
- // When we need to locate the a_frame
- switch( type )
- {
- case 1:
- case 2:
- // Some transitions (esp. audio) may accept blank frames
- active = accepts_blanks;
-
- // If we're not active then...
- if ( !active )
- {
- // Hunt for the a_frame
- while( a_frame <= b_frame && invalid( this->frames[ a_frame ] ) )
- a_frame ++;
-
- // Determine if we're active now
- active = a_frame != b_frame && !invalid( this->frames[ b_frame ] );
- }
- break;
-
- default:
- mlt_log( service, MLT_LOG_ERROR, "invalid transition type\n" );
- break;
- }
-
- // Now handle the non-always active case
- if ( active && !always_active )
- {
- // For non-always-active transitions, we need the current position of the a frame
- position = mlt_frame_get_position( this->frames[ a_frame ] );
-
- // If a is in range, we're active
- active = position >= in && position <= out;
- }
-
- // Finally, process the a and b frames
- if ( active )
- {
- mlt_frame a_frame_ptr = this->frames[ !reverse_order ? a_frame : b_frame ];
- mlt_frame b_frame_ptr = this->frames[ !reverse_order ? b_frame : a_frame ];
- int a_hide = mlt_properties_get_int( MLT_FRAME_PROPERTIES( a_frame_ptr ), "hide" );
- int b_hide = mlt_properties_get_int( MLT_FRAME_PROPERTIES( b_frame_ptr ), "hide" );
- if ( !( a_hide & type ) && !( b_hide & type ) )
- {
- // Process the transition
- *frame = mlt_transition_process( this, a_frame_ptr, b_frame_ptr );
-
- // We need to ensure that the tractor doesn't consider this frame for output
- if ( *frame == a_frame_ptr )
- b_hide |= type;
- else
- a_hide |= type;
-
- mlt_properties_set_int( MLT_FRAME_PROPERTIES( a_frame_ptr ), "hide", a_hide );
- mlt_properties_set_int( MLT_FRAME_PROPERTIES( b_frame_ptr ), "hide", b_hide );
- }
- }
- }
-
- // Obtain the frame from the cache or the producer we're attached to
- if ( index >= a_track && index <= b_track )
- *frame = this->frames[ index ];
- else
- error = mlt_service_get_frame( this->producer, frame, index );
-
- // Determine if that was the last track
- this->held = !mlt_properties_get_int( MLT_FRAME_PROPERTIES( *frame ), "last_track" );
-
- return error;
-}
-
-/** Close and destroy the transition.
- *
- * \public \memberof mlt_transition_s
- * \param this a transition
- */
-
-void mlt_transition_close( mlt_transition this )
-{
- if ( this != NULL && mlt_properties_dec_ref( MLT_TRANSITION_PROPERTIES( this ) ) <= 0 )
- {
- this->parent.close = NULL;
- if ( this->close != NULL )
- {
- this->close( this );
- }
- else
- {
- mlt_service_close( &this->parent );
- free( this->frames );
- free( this );
- }
- }
-}
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